(a) Technical Field of the Invention
The present invention generally relates to optical fibers, and more particularly to a coupling assembly comprising coupler and connectors for tight joining of the cores of fiber cables.
(b) Description of the Prior Art
The introduction of fiber optics has dramatically changed how telecommunications is conducted. Using lights as carriers and fiber cables to deliver light signals precisely and accurately, fiber optics provides signal transmissions far superior than conventional means and, therefore, relevant industries have emerged around the field of fiber optics.
In real-life applications, it is often required to join two fiber cables together using passive devices such as couplers. An ideal coupler should be able to provide low power loss, reliability in terms of frequent connection and disconnection, durability under harsh environment, and easy installation. Currently, a common fiber coupler establishes physical contact between two fiber cables by receiving the connectors installed at the ends of the fiber cables into the through channels inside the coupler. Usually a spring or other similar device inside the coupler exerts pressure on the connectors so that the cores of the fiber cables are in close contact with each other, and light signals could thereby be transmitted from one fiber cable to another.
For example, both the U.S. Pat. No. 5,359,688 and Republic of China, Taiwan, Patent No. 302,441 discloses different connector and coupler designs for joining a single pair of fiber cables. The connectors according to these teachings contain multiple components arranged in a complicated structure. Therefore, not only the installation of the connectors becomes troublesome, but also the coupler requires a larger form factor so as to accommodate the more complicated connectors. In user environments where facility space is tight, the bulky couplers would provide only a limited number of cable couplings.
U.S. Pat. No. 5,719,977 therefore discloses a design which achieves a coupler having a smaller form factor by utilizing specially-shaped connectors. Compared with conventional connectors and couplers, the design is able to provide an additional pair of fiber cable coupling within a compatible dimension. The space saving of the teaching, however, is compromised by the additional requirement of increased precision in the production of reduced-sized components. For example, the diameter of the connector's tubular plug is reduced from the conventional 2.5 mm to 1.25 mm, making the manufacturing process much more difficult and, therefore, increasing the production cost dramatically.
Accordingly, an improved design is required so as to strike a balance between the requirements for scaling down the component sizes and for reducing operation difficulty and production cost.